Question

find the rate of compound interest of 6500 so that it amount to rupees 7865 into years​

Answer 1

21% is the interest rate. Ans

Answer 2

Given :

Amount = Rs. 7865

Sum = 6500

Time = 2 years

To find : rate of interest = ?

Solution :

Using "Compound  interest " , we get :

$A=P(1+\dfrac{r}{100})^n\\\\7865=6500(1+\dfrac{r}{100})^2\\\\\dfrac[7865}{6500}=(1+\dfrac{r}{100})^2\\\\1.21=(1+\dfrac{r}{100})^2\\\\\sqrt{1.21}=(1+\dfrac{r}{100})\\\\1.1=1+\dfrac{r}{100\\\\1.1-1=\dfrac{r}{100}\\\\0.1=\dfrac{r}{100}\\\\0.1\times 100=r\\\\r=10\%$

Hence, the rate of interest is 10%.